#include <iostream>
using namespace std;

int main() {

    int score;
    cin >> score;

    // write your code here......
    if (score < 0 || score > 100) {
        cout << "成绩不合法" << endl;
    } else if (score < 60) {
        cout << "差" << endl;
    } else if (score < 70) {
        cout << "及格" << endl;
    } else if (score < 80) {
        cout << "中" << endl;
    } else if (score < 90) {
        cout << "良" << endl;
    } else {
        cout << "优秀" << endl;
    }

    return 0;
}